Bone marrow autotransplantation

Ectopic expression of CDX4 in human mesenchymal stem cells does not affect HOX gene expression or induce hematopoietic reprogramming

In vitro generation of large numbers of autologous hematopoietic stem cells would be extremely useful for clinical applications. Adipose tissue derived mesenchymal stem cells (AT-MSC) are an easily available autologous source for cell therapy applications. Like hematopoietic cells, MSC are of mesodermal origin. The Cdx-Hox pathway is an important genetic program for hematopoiesis, where Cdx4 is a key upstream regulator of the Hox family. We introduced ectopic CDX4 gene in an attempt to reprogram AT-MSC to differentiate along the hematopoietic lineage. To further promote hematopoietic reprogramming, we cultured the transduced cells in cocktails of hematopoietic cytokines, growth factors or epigenetic modifiers. However, despite strong expression of CDX4 at the mRNA and protein levels, neither downstream HOX genes, other genes of importance for hematopoietic development or functional colony forming assays showed any evidence of hematopoietic reprogramming. Thus, despite the close developmental association between these cell types, the introduction of one single master switch transcription factor was not sufficient to promote hematopoietic reprogramming in AT-MSC.

Analysis for recovery and loss of mononuclear cells and colony-forming units granulocyte-macrophage during ex vivo processing of autologous bone marrow

During ex vivo processing of autologous bone marrow (BM) substantial loss of stem and progenitor cells should be avoided to achieve rapid and sustained hematopoietic reconstitution after high-dose radio-/chemotherapy. We processed 25 autologous BM grafts with the Fresenius AS104 cell separator for cryopreservation and we determined recoveries for mononuclear cells (MNC) and colonyforming units granulocyte-macrophage (CFU-GM) in the BM concentrates. To identify cell loss in BM fractions not cryopreserved, we investigated the MNC and CFU-GM content of BM fat and BM blood. MNC and CFU-GM recovery yielded a mean ( +/- SEM) of 42 +/- 12 and 54 +/- 20% in the BM concentrate. BM fat showed a mean loss of 7 +/- 5% for MNC and 4 +/- 3% for CFU-GM, BM blood 30 +/- 12% for MNC and 13 +/- 13% for CFU-GM, respectively. CFU-GM recovery was significantly higher in the BM concentrate of patients with hematologic malignancy (HM) compared with patients suffering from germ cell cancer (GCC): 66 +/- 21 vs. 43 +/- 12% (p < 0.02). Seventeen patients (7 GCC, 10 HM) underwent high-dose chemotherapy or radio-/chemotherapy and were autografted with 0.8 +/- 0.2 x 10(8) MNC/kg and 3.7 +/- 2.0 x 10(4) CFU-GM/kg. All patients achieved engraftment with neutrophils > 0.5 x 10(9)/l at a mean of 14 +/- 6 days. We conclude that: (1) ex vivo processing of autologous BM with a mean of recovery of 42% for MNC and 54% for CFU-GM in the BM concentrate can result in a cell population capable of sustained hematopoietic reconstitution, (2) CFU-GM recovery is significantly higher in patients with HM than in patients with GCC and (3) 37% MNC and 17% CFU-GM represent in fact cell losses recovered from BM fractions not cryopreserved (BM fat, BM blood). Furthermore, it is likely that MNC and CFU-GM not recovered from BM concentrate, BM fat and BM blood are cell losses related to the cell separator.

Potentiation of merocyanine 540-mediated photodynamic therapy by salicylate and related drugs

Simultaneous exposure to merocyanine 540 (MC540) and light of a suitable wavelength kills leukemia, lymphoma and neuroblastoma cells but is relatively well tolerated by normal pluripotent hematopoietic stem cells. This differential phototoxic effect has been exploited in preclinical models and a phase I clinical trial for the extracorporeal purging of autologous bone marrow grafts. Salicylate is known to potentiate the MC540-mediated photokilling of tumor cells. Assuming that salicylate induces a change in the plasma membrane of tumor cells (but not normal hematopoietic stem cells) that enhances the binding of dye molecules it has been suggested that salicylate may provide a simple and effective means of improving the therapeutic index of MC540-mediated photodynamic therapy. We report here on a direct test of this hypothesis in a murine model of bone marrow transplantation as well as in clonal cultures of normal murine hematopoietic progenitor cells. In both systems, salicylate enhanced the MC540-sensitized photoinactivation of leukemia cells and normal bone marrow cells to a similar extent and thus failed to improve the therapeutic index of MC540 significantly. On the basis of a series of dye-binding studies, we offer an alternative explanation for the potentiating effect of salicylate. Rather than invoking a salicylate-induced change in the plasma membrane of tumor cells, we propose that salicylate displaces dye molecules from serum albumin, thereby enhancing the concentration of free (active) dye available for binding to tumor as well as normal hematopoietic stem cells.

Hemopoietic growth and inhibitory factors in treatment of malignancies. A review

The clinical use of cytokines is still expanding as the knowledge of beneficial effects as adjunct to cancer treatment is increasing. G-CSF and GM-CSF stimulates hemopoietic recovery after myelosuppressive chemotherapy and enhances engraftment after bone marrow transplantation. New cytokines as IL-1, IL-3, IL-4 and IL-6, are studied in clinical trials and combinations of these with stem cell factor seem promising in ex vivo expansion of stem cells. GM-CSF also have antitumor effects. The most recently discovered hemopoietic growth factor is thrombopoietin, from which probably especially patients with leukemia will benefit.

Feasibility and toxicity study of a high-dose chemotherapy regimen for autotransplantation incorporating carboplatin, cyclophosphamide and thiotepa

Sixteen patients received a high-dose chemotherapy regimen consisting of carboplatin (1600 mg/m2) and cyclophosphamide (6000 mg/m2) as daily two-hour infusions over four days (CC). All but two of them also received thiotepa (480 mg/m2) in eight 30-minute infusions given every 12 hours (CTC). Bone marrow and/or peripheral stem cell (PSC) reinfusions took place 72 hours after the last course of chemotherapy. The major toxicity was bone marrow suppression, the duration of which was markedly reduced in the patients receiving PSC reinfusions. Non-hematological toxicity was relatively mild and consisted of nausea and vomiting, minor mucositis and skin rashes. All but one patient had mild and completely reversible elevations of serum ALAT and/or LDH levels. One patient, who had received full-dose chemotherapy despite a creatinine clearance of 56 ml/min, developed significant toxicity consisting of transient cyclophosphamide-associated pancarditis, reversible neurotoxicity and partially reversible hearing loss and renal function impairment. There were no toxic deaths. In view of the high carboplatin dose, the CTC regimen may be particularly suitable for use in the salvage treatment of germ cell cancer. Since CTC causes no serious organ toxicity, further studies to determine its suitability for double or even triple transplantation programs are warranted.

Variations of plasma sialic acid and N-acetylglucosamine levels in cancer, inflammatory diseases and bone marrow transplantation: a proton NMR spectroscopy study

Proton NMR spectroscopy allows the detection in plasma of resonances arising from N-acetyl-glucosamine (NAG) and N-acetyl-neuraminic acid (NANA) which have been shown to be borne by acute phase glycoproteins. These resonances can be identified using 2 different protocols of spectrum acquisition detecting different physical states in the global pool of glycoproteins, ie mobile and less mobile moieties of glycosylated chains. In this study we demonstrate that NMR spectroscopy allows a precise monitoring of the variations of glycosylated residues in cancers, inflammatory processes and bone marrow transplantation. The most important findings are that: i), the distribution of glycosylated residues varies with the origin of the cancerous tissue; ii), the level of these residues is a function of tumor development; iii), the concentrations in NAG and NANA are well correlated with the standard biological parameters of acute phase and leucocyte activation. Proton NMR spectroscopy of glycosylated residues in plasma may offer a new means of monitoring sialic acid in cancer and other pathological conditions.

Autologous marrow transplantation for Hodgkin's disease current techniques and prospects

Hodgkin's disease is a chemotherapeutically curable malignancy, but cure is rare if a complete remission is not achieved with initial therapy. Drugs that have myelosuppression as a major dose-limiting toxic effect, can be given at high doses and may be combined together at close to the maximum tolerated dose with marrow rescue. Multiple chemotherapy drugs given at high doses with marrow rescue are best utilized if they possess dissimilar extramedullary toxicity. The use of growth factors and improved storage methods may also help reduce hematopoietic toxicity. There is currently no consensus on the ideal treatment regimen, although combinations of etoposide, carmustine, and cyclophosphamide are frequently used and are associated with decent disease-free survival. The frequency of pulmonary complications is higher with regimens containing higher doses of carmustine. There are no prospective comparative randomized trials between standard chemotherapy and high dose chemotherapy with marrow support. Patients transplanted earlier in the course of their disease appear to do best, as do patients with good performance status and low tumor burden who have had less than two prior regimens. In such patients the long-term disease-free survival after autologous bone marrow transplantation may be in excess of 80%. Patients with Hodgkin's disease refractory to front line chemotherapy do poorly with high dose chemotherapy with autologous marrow rescue and often do not achieve remission. Newer regimens need to be explored and developed for patients at high risk of relapse.